Various head mounted displays are available. Users of head mounted displays have different requirements depending upon the application. For example, users of head mounted displays for remote conferencing, industrial processing, and surgical procedures will each have different requirements for the head mounted displays. Further, within a particular application, such as surgical procedure applications for head mounted displays, users also have different requirements or different needs. For example, in surgical procedures, head mounted displays must be adjustable with respect to the user's eyes, provide easy and fatigue-free viewing, provide dimensional viewing compatible with sensors (e.g., two dimensional and three dimensional viewing), limit interference with the surgeon's capability to perform surgery, etc.
One head mounted display available from Kaiser Electro-Optics, Inc. (Carlsbad, Calif.) under the trade designation ProView.TM., provides various adjustments to adapt the head mounted display to a wide variety of users and applications. For example, Kaiser Electro-Optics displays provide interpupillary distance adjustment to allow the viewing modules or image sources to be properly adjusted to accommodate a wide range of viewers or users. Further, a height adjustment feature on the head mounted display allows positioning of the viewing modules or image sources for viewing. In addition, a horizontal adjustment allows the user to change the distance between the eyes of the user and the image sources or viewing modules so as to accommodate eyeglasses or safety glasses. Further, such adjustable head mounted displays include a tilt feature which allows the image source or viewing module to be rotated or tilted relative to the eyes such that the user can look up at the display or view the image source and keep the eyes on the particular work being performed. In addition, such tilt adjustment allows the user to flip the entire image source up and out of the way if the user wishes to take a break from work or viewing of the image source.
However, such currently available head mounted displays, including the Kaiser Electro-Optics displays, have associated drawbacks. For example, such head mounted displays require multiple adjustment mechanisms and multiple steps for adjusting the display or viewing modules relative to the user's eyes to achieve desired positioning of the image modules or sources for the user's applications. This is particularly problematic in applications where adjustment of the position of the image sources relative to the eyes of the user are to be performed as quickly and easily as possible with little interruption to the user.
For example, in a surgical application the user may need to adjust the position of a viewing module or image source as surgical procedures are being performed. Such adjustment may need to be made by an assistant at the surgical site as opposed to the user who is wearing the head mounted display so as to keep the surgical site sterile. Further, such adjustments during the surgical procedures must be made quickly to minimize interruption to the user's surgical procedure. The adjustments must also be intuitive to the user, e.g., unnecessary training to accomplish such adjustments must be minimized and/or the adjustment procedure must not be complicated. Likewise, head mounted displays used for such applications should have an open field of view to the user. For example, the position of cabling relative to the viewing modules for providing video signal thereto should minimize interruption in the field of view and also prevent any cable from snagging on other equipment in the surgical field. Conventional head mounted displays typically have service loops associated with the cabling, such as cabling which is provided to the rear of the user's head from the image modules through temporal supports of the headband suspending the display. Such service loops may interrupt the user's field of view and may snag on equipment in the surgical field.